The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose⁃catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monit...The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose⁃catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16℃in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni⁃NTA affinity column.Size⁃exclusion chromatography and SDS⁃PAGE analysis demonstrated that the puri⁃fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD^(+)as a coenzyme to NADP^(+).The optimal temperature and pH of the TeXDH were 40℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26%of the initial enzyme activity,while the divalent metal ions Mg^(2+)or Ca^(2+)could recover the enzyme activity of TeXDH,reaching 103.32%and 110.69%of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn^(2+),Ni^(2+),Cu^(2+),Zn^(2+),Co^(2+),and Cd^(2+)significantly inhibited the activity of TeXDH.ICP⁃MS and molecular doc⁃king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn^(2+)ions and 1 mol/L Mg^(2+)ion.Further⁃more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.展开更多
REST(Rust-based electronic structure toolkit)is a modern open-source electronic structure code entirely written in Rust,combining high performance,memory safety,and expressive concurrency.As a community-driven project...REST(Rust-based electronic structure toolkit)is a modern open-source electronic structure code entirely written in Rust,combining high performance,memory safety,and expressive concurrency.As a community-driven project,its source code is freely available at https://gitee.com/restgroup,fostering open collaboration and transparent development.It supports a wide range of density functional methods-from local density approximation(LDA),generalized gradient approximation(GGA),meta-GGA,and hybrids to doubly hybrids,as well as machine learning-augmented functionals-enabling high-accuracy simulations with low computational overhead.Its“disk-free”RI-based(RI:resolution-of-the-identity)implementation and efficient shared-memory parallelism(via Rayon)ensure rapid calculations even for challenging systems.REST also of-fers unique user support through large language model-assisted input generation and develop-erfriendly tensor libraries for rapid algorithm prototyping.展开更多
基金湖南省教育厅基金优秀青年项目(No.22B0482)湖南科技大学博士启动基金(No.E51992 and E51993)资助。
文摘The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose⁃catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16℃in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni⁃NTA affinity column.Size⁃exclusion chromatography and SDS⁃PAGE analysis demonstrated that the puri⁃fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD^(+)as a coenzyme to NADP^(+).The optimal temperature and pH of the TeXDH were 40℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26%of the initial enzyme activity,while the divalent metal ions Mg^(2+)or Ca^(2+)could recover the enzyme activity of TeXDH,reaching 103.32%and 110.69%of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn^(2+),Ni^(2+),Cu^(2+),Zn^(2+),Co^(2+),and Cd^(2+)significantly inhibited the activity of TeXDH.ICP⁃MS and molecular doc⁃king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn^(2+)ions and 1 mol/L Mg^(2+)ion.Further⁃more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.
基金supported by the National Natural Science Foundation of China (Nos. 22125301, 22393911, 22393912, 22321003, 22233002)the Innovation Program for Quantum Science and Technology (2021ZD0303305)the robotic AI-Scientist platform of the Chinese Academy of Science。
文摘REST(Rust-based electronic structure toolkit)is a modern open-source electronic structure code entirely written in Rust,combining high performance,memory safety,and expressive concurrency.As a community-driven project,its source code is freely available at https://gitee.com/restgroup,fostering open collaboration and transparent development.It supports a wide range of density functional methods-from local density approximation(LDA),generalized gradient approximation(GGA),meta-GGA,and hybrids to doubly hybrids,as well as machine learning-augmented functionals-enabling high-accuracy simulations with low computational overhead.Its“disk-free”RI-based(RI:resolution-of-the-identity)implementation and efficient shared-memory parallelism(via Rayon)ensure rapid calculations even for challenging systems.REST also of-fers unique user support through large language model-assisted input generation and develop-erfriendly tensor libraries for rapid algorithm prototyping.
